The present invention relates to control of components within a motor vehicle utilizing an on-board computer network; and more particularly to a process for sequentially executing a plurality of motor vehicle programs on the computer network.
Computer systems are finding greater application in motor vehicles, for engine control, dashboard displays and passenger comfort systems for example. This applies not only to passenger automobiles, but also to trucks such as long haul semi-trailer trucks. Computer systems allow monitoring and display of the functional performance of the truck, as well as vehicle tracking, guidance and logging of information required by governmental authorities. It is desirable to integrate all of these functions into one on-board computer. That integration allows the driver to select among available features and have the relevant information presented on a common display device within the truck cab.
Although it is possible to enable all of the software programs for these features to execute simultaneously on the computer, such simultaneous execution requires a relatively high speed, sophisticated microcomputer and other components. Thus such simultaneous execution significantly increases the cost of the computer system and it is always desirable to minimize the cost of any system. Therefore, it is preferable to enable the motor vehicle computer system to load and execute only the application program that implements the specific function selected by the driver. Similarly it is desirable to load only the interface routines which are required by that application program. In other words, a particular application program may not require access to certain network components and thus the interface routines for those components do not have to be loaded for execution. For example if the driver selects the application to monitor engine performance, that application does not require access to an external communication device, such as a cellular telephone, used to exchange data between the truck and a dispatch facility of the trucking company.